At least 40 rail passengers have died and 80 more have been wounded after a commuter train derailed in south-east London.

The 19:43 express train was travelling from Hastings to Charing Cross when at 21:16 it crashed off the rails between Hither Green and Grove Park stations near the Southern Region Continental goods depot.

It happened just over a mile from the scene of the Lewisham train crash in 1957 in which 90 people were killed and 175 were injured.

Only the first two of the train's 12 coaches remained on the rails. One overturned completely and the next two jack-knifed onto their sides.

Tonight, rescuers working under floodlights are trying to free those still trapped in them. Driving rain and the position of some of the overturned coaches has made the rescue operation especially difficult.

'Terrible screams'

Firemen are using special equipment to cut through many coaches to release passengers.

Hospital medical teams and ambulances are at the crash site and doctors have had to crawl through twisted wreckage to treat survivors and give them painkilling injections.

Most of the survivors were taken to Lewisham hospital, praised for its work after the Lewisham train disaster ten years ago.

The driver and guard escaped unharmed but remain in a state of shock.

Eyewitnesses have been describing the accident to journalists.

Shirley Ward, a 21-year-old secretary from Broadstairs in Kent who emerged unharmed from the wreckage, told the Times newspaper: "The lights went out before we turned over. We felt ourselves travelling along on the carriage's side. Everyone was clutching on to one another. There were some terrible screams."

Another survivor, 19-year-old medical student Ray Moore from Hastings, said: "Stones came chipping up from the track as we went along this stretch which is usually a pretty fast one.

"Then it rocked and swayed and went over on its side. At least three people in my compartment were killed."

A spokesman for the British Railways Board said it was not know what caused the derailment. He said: "It is wide open what could have happened. [The train] could have crossed points or hit an obstruction."